//
// Copyright © 2020, 2021 Anticrm Platform Contributors.
//
// Licensed under the Eclipse Public License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License. You may
// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//
// See the License for the specific language governing permissions and
// limitations under the License.
//

import {
  type MigrateOperation,
  type MigrateUpdate,
  type MigrationClient,
  type MigrationDocumentQuery,
  type MigrationUpgradeClient,
  tryMigrate
} from '@hcengineering/model'
import { DOMAIN_PREFERENCE } from '@hcengineering/preference'
import view, { type Filter, type FilteredView, type ViewletPreference, viewId } from '@hcengineering/view'
import { getSocialKeyByOldAccount, getUniqueAccounts } from '@hcengineering/model-core'
import { type AccountUuid, MeasureMetricsContext } from '@hcengineering/core'

import { DOMAIN_VIEW } from '.'

async function removeDoneStatePref (client: MigrationClient): Promise<void> {
  const prefs = await client.find<ViewletPreference>(DOMAIN_PREFERENCE, {
    _class: view.class.ViewletPreference,
    config: 'doneState'
  })
  for (const pref of prefs) {
    await client.update(DOMAIN_PREFERENCE, { _id: pref._id }, { config: pref.config.filter((p) => p !== 'doneState') })
  }
  const lookupPrefs = await client.find<ViewletPreference>(DOMAIN_PREFERENCE, {
    _class: view.class.ViewletPreference,
    config: '$lookup.doneState'
  })
  for (const pref of lookupPrefs) {
    await client.update(
      DOMAIN_PREFERENCE,
      { _id: pref._id },
      { config: pref.config.filter((p) => p !== '$lookup.doneState') }
    )
  }
}

async function removeDoneStateFilter (client: MigrationClient): Promise<void> {
  const filters = await client.find<FilteredView>(DOMAIN_VIEW, {
    _class: view.class.FilteredView
  })
  for (const filter of filters) {
    let changed = false
    const options = filter.viewOptions
    if (options != null) {
      if (options.orderBy[0] === 'doneState') {
        options.orderBy[0] = 'status'
        changed = true
      }
      if (options.groupBy.includes('doneState')) {
        changed = true
        options.groupBy = options.groupBy.filter((g) => g !== 'doneState')
        if (options.groupBy.length === 0) {
          options.groupBy[0] = 'status'
        }
      }
    }
    let filters = JSON.parse(filter.filters) as Filter[]
    const initLength = filters.length
    filters = filters.filter((p) => p.key.key !== 'doneState')
    if (initLength !== filters.length) {
      changed = true
    }
    if (changed) {
      await client.update(DOMAIN_VIEW, { _id: filter._id }, { viewOptions: options, filters: JSON.stringify(filters) })
    }
  }
}

async function migrateAccountsToSocialIds (client: MigrationClient): Promise<void> {
  const ctx = new MeasureMetricsContext('view migrateAccountsToSocialIds', {})
  const socialKeyByAccount = await getSocialKeyByOldAccount(client)

  ctx.info('processing view filtered view users ', {})
  const iterator = await client.traverse(DOMAIN_VIEW, { _class: view.class.FilteredView })

  try {
    let processed = 0
    while (true) {
      const docs = await iterator.next(200)
      if (docs === null || docs.length === 0) {
        break
      }

      const operations: { filter: MigrationDocumentQuery<FilteredView>, update: MigrateUpdate<FilteredView> }[] = []

      for (const doc of docs) {
        const filteredView = doc as FilteredView

        if (filteredView.users === undefined || filteredView.users.length === 0) continue

        const newUsers = filteredView.users.map((u) => socialKeyByAccount[u] ?? u)

        operations.push({
          filter: { _id: filteredView._id },
          update: {
            users: newUsers as any
          }
        })
      }

      if (operations.length > 0) {
        await client.bulk(DOMAIN_VIEW, operations)
      }

      processed += docs.length
      ctx.info('...processed', { count: processed })
    }
  } finally {
    await iterator.close()
  }
  ctx.info('finished processing view filtered view users ', {})
}

async function migrateSocialIdsToGlobalAccounts (client: MigrationClient): Promise<void> {
  const ctx = new MeasureMetricsContext('view migrateSocialIdsToGlobalAccounts', {})
  const accountUuidBySocialKey = new Map<string, AccountUuid | null>()

  ctx.info('processing view filtered view users ', {})
  const iterator = await client.traverse(DOMAIN_VIEW, { _class: view.class.FilteredView })

  try {
    let processed = 0
    while (true) {
      const docs = await iterator.next(200)
      if (docs === null || docs.length === 0) {
        break
      }

      const operations: { filter: MigrationDocumentQuery<FilteredView>, update: MigrateUpdate<FilteredView> }[] = []

      for (const doc of docs) {
        const filteredView = doc as FilteredView

        if (filteredView.users === undefined || filteredView.users.length === 0) continue

        const newUsers = await getUniqueAccounts(client, filteredView.users, accountUuidBySocialKey)

        operations.push({
          filter: { _id: filteredView._id },
          update: {
            users: newUsers
          }
        })
      }

      if (operations.length > 0) {
        await client.bulk(DOMAIN_VIEW, operations)
      }

      processed += docs.length
      ctx.info('...processed', { count: processed })
    }
  } finally {
    await iterator.close()
  }
  ctx.info('finished processing view filtered view users ', {})
}

export const viewOperation: MigrateOperation = {
  async migrate (client: MigrationClient, mode): Promise<void> {
    await tryMigrate(mode, client, viewId, [
      {
        state: 'remove-done-state-pref',
        mode: 'upgrade',
        func: removeDoneStatePref
      },
      {
        state: 'remove-done-state-filter',
        mode: 'upgrade',
        func: removeDoneStateFilter
      },
      {
        state: 'accounts-to-social-ids',
        mode: 'upgrade',
        func: migrateAccountsToSocialIds
      },
      {
        state: 'social-ids-to-global-accounts',
        mode: 'upgrade',
        func: migrateSocialIdsToGlobalAccounts
      }
    ])
  },
  async upgrade (state: Map<string, Set<string>>, client: () => Promise<MigrationUpgradeClient>): Promise<void> {}
}